Academics and policy-makers have expressed concern that neighborhood quality affects numerous economic and social outcomes of residents, including health and development outcomes of children and adolescents. Despite this concern regarding neighborhood quality, relatively little is understood about the process by which neighborhoods typically improve or decline. This project is designed to investigate and describe the characteristics of neighborhood change. How much of the change arises from the changing composition of residents due to in and out-migration? How much is due to changing outcomes of existing residents? How are both the changes in mobility and changes in individual outcomes associated with neighborhood change distributed across different demographic groups? We use two confidential data sources: the non-public use American Housing Survey (AHS) national sample, covering 1985-2005, and the 1990 and 2000 Decennial Long Form samples. Because both of these micro-data sources identify census tract of residence, we can decompose the observed change in aggregate neighborhood outcomes into that due to changes in mobility rates, changes in characteristics and outcomes of the migrants, and changes in outcomes of the existing residents. Because of our use of large micro-data sets, we will be able to disaggregate the mobility and outcome components of neighborhood change by demographic characteristics -- specifically race/ethnicity, age, education, presence of school-aged children and homeownership status. We will further consider how neighborhood change varies across different neighborhood contexts, specifically by disaggregating our analysis by neighborhood income and neighborhood income growth, as well as racial/ethnic concentration and change in racial/ethnic concentration. Our proposed analysis will provide detailed insight into the fundamental nature of neighborhood change. Our study considers the underlying features of neighborhood change and neighborhood quality. Academics and policy-makers have expressed concern that neighborhood quality affects numerous economic and social outcomes of residents, including health and development outcomes of children and adolescents.